What does the Digestion and circulation module cover?

This module gathers the digestion and circulation content of Biology 1 in WJEC GCSE Science Double Award. It covers the organs of the digestive system, the carbohydrase, protease and lipase enzymes and the food tests for starch, sugar, protein and fat, how the villi absorb digested food, the structure of the heart and the double circulation, the arteries, veins and capillaries, the components of blood, and coronary heart disease.

Which unit and paper assess this module?

These topics are part of Unit 1 (Biology 1), a written paper of 1 hour 15 minutes worth 15 percent of the Double Award qualification, sat at Foundation or Higher tier. Questions mix recall, the food-test practical and explanation, including data on heart disease.

What practical skills are needed here?

You need to carry out and describe the food tests: iodine for starch, Benedict's (with heating) for reducing sugar, biuret for protein and the emulsion test for fat, including using a control. You should also be able to interpret data on the components of blood and the risk factors for coronary heart disease.

What kinds of question come up?

Expect questions naming digestive organs and their functions, describing the role of bile, matching enzymes to their food group and products, describing food tests and their colour changes, explaining how the villi are adapted, comparing the left and right sides of the heart, comparing arteries and veins, naming the components of blood, and explaining the cause and treatment of coronary heart disease.

How should I revise this module?

Learn the digestive organs and the action of each enzyme, and memorise the four food tests with their reagents and colour changes. Link every villus and red-blood-cell adaptation to its function, and learn the structure of the heart and the differences between the blood vessels. Use WJEC Double Award past papers and watch the command words such as Describe, Explain and Compare.

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WJEC GCSE Science Double Award: Digestion and circulation (Unit 1, Biology 1) overview

An overview of the Digestion and circulation module in WJEC GCSE Science Double Award (Unit 1, Biology 1), mapping the digestive system, digestive enzymes and food tests, absorption of digested food, the heart and circulation, and blood and circulatory health.

Generated by Claude Opus 4.86 min readDouble Award Unit 1 (Biology 1)Updated 2026-06-15

Reviewed by: AI editorial process; not yet individually human-reviewed

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The topics in this module
How this module fits the exam
How to study this module

The Digestion and circulation module gathers the digestion and transport content of Biology 1 in WJEC GCSE Science Double Award. It explains how food is broken down and absorbed, and how the heart and blood vessels move substances around the body. This page maps the module and links to a focused answer page for each part.

The topics in this module

The digestive system: The digestive organs and their functions, mechanical and chemical digestion, and the role of bile. See The digestive system.
Digestive enzymes and food tests: Carbohydrase, protease and lipase and their products, and the iodine, Benedict's, biuret and emulsion tests. See Digestive enzymes and food tests.
Absorption of digested food: How the soluble products are absorbed and how the villi are adapted. See Absorption of digested food.
The heart and circulation: The structure of the heart, the double circulation, and arteries, veins and capillaries. See The heart and circulation.
Blood and circulatory health: The components of blood and coronary heart disease. See Blood and circulatory health.

How this module fits the exam

These topics sit in Unit 1 (Biology 1), a written paper of 1 hour 15 minutes worth 15%. Questions mix recall (organs, enzymes, blood parts), the food-test practical, and explanation (villi adaptations, the heart, heart disease).

How to study this module

Learn the organs and enzymes. Know each digestive organ, each enzyme and its product.
Memorise the food tests. Reagent and colour change for starch, sugar, protein and fat.
Link adaptation to function. Villi and red blood cells must each be explained.
Know the heart and vessels. The four chambers, the double circulation and the artery/vein/capillary differences.
Understand heart disease. Its cause, effects and treatments (stents, statins, lifestyle).

Then test yourself with the module quiz.

Sources & how we know this

WJEC GCSE Science (Double Award) specification (from 2016) — WJEC (2016)